Centrifugal pipe casting apparatus



Jan- 14,1936 N. F'. s. RUSSELL Erm. 2,027,453

CENTRIFUGAL PIPE CASTING APPARATUS Jan. 14, 1936. N. F. s. RussLl. erA1. 2,027,453

i CENTRIFUGAL PIPE CASTING APPARATUS 5 Sheets-Sheet 2 NN f u ww* a ww. Qm WMHHHF ..2 l QH -...H.............-......H-- -f l gl, M h @NNN Jan.14, 1936.

N. F. S. RUSSELL ET AL GENTRIFUGAL PIPE CASTING APPARATUS Filed Nov. 3,1934 5 Sheets-Sheet 3 Mmmm/F5. wssell i Jan. 14, 1936.5

N. S. RUSSELL Er AL CENTRIFUGAL PUE CASTING APPARATUS Filed Nov. 3, 19345 Sheets-Sheet 4 Jjwentr Fussell diy Jan. 14, 1936. NI F, s, RUSSELL AL2,027,453

CENTRIFUGAL PIPE CASTING APPARATUS Filed Nov. s, 1954 `5 sheets-sheet 5F4 lf3 Z E4 J 5 ks l i h .17H/@Rims /armanl Fuss ell 6r Patented Jan.14,,1936

UNITED STATES PATENT OFFICE CENTRFUGAL PIPE CASTING APPARATUS Norman F.S. Russell 'and Frederick C. Langenberg, Edgewater Park, N. J.,lassignors to United States Pipe and Foundry Company, Burlington, N. J.,a corporation of New Jersey ApplicationY November 3, 1934, Serial No.751,318

16 Claims. (Cl. 22-65') of centrifugal pipe casting apparatus in which(the metal is delivered by the chute to. a trough having a delivery spoutat its end and through said trough and spout to avrelati/velyreciprocable l mold, which mold is rotatable and usually lo.- cated in awater box or equivalent cooling mechanism, supported on a reciprocablecarriage and so actuated as to bring about a progressive delivery ofmolten metal from one end to the other of v20 the mold. As heretoforeconstructed, the chutes through which the molten metal passes have beenconstructed with downwardly inclinedchannels having converging sidewalls sufficiently far apart at the point where the metal from th/eladle con- .25 tacts with the chute to receive the stream of metalbetween them and converging in such man- /ner that the breadth of thechannel at the de-- livery cnd of the chute corresponds with the breadthof the channelin the trough and it'has 30 been found that at timesdisgured and defective pipe castings are formed owing to the fact thatnot infrequently fins or sprays of molten metal are thrown' upward andforward from the surface of the metal stream passing through the chute,

.35' some of which'enter the mold and give rise` to defective castings.Again, it has been found that the metal stream delivered to the troughis at times soY turbulent` as to bring about i a splashing of the'metalpassing through the 40 trough over its edges which again resultsin more or less -defective pipes and, again, it has been found that attimes the stream of metal issuing from the spout at the end of theVtrough is so tur-y .l

bulent as to bring about a splashing of a portion 45 of the deliveredmetal which, again, may result in the production of more or lessdefective pipes andit 'is the object o! our invention to so constructand combine'the chute with the other parts ofthe casting apparatusl asto' prevent or 50 greatly -lessen the tendency of the metallic' streampassing through the chute to throw out a spray' and at the Sametime tocause the metal to ow throughthe chute and vtrough with a minimum ofturbulence and so as to greatly lessen the oc/-j `v55 currence ofsplashes from the trough and of o and adapted to deliver a stream ofmolten metal splashingl at the delivery spout of the trough. It/` is afurther object of our invention to so modify and reconstruct thestructure for supporting the trough in the proper alignment with themold as to adapt the structure for use with the improved 5 constructionof the chute and also to provide an improved structure which willresult'in a more perfectalignment of the chute withl the channel formedin the trough than has heretofore been practical. l0

Itis, of course, well known that a falling stream of a liquid, such asmolten cast iron, will fall with aconstant acceleration and with .acorresponding decrease in cross-sectional area and. also that a fallingstream of liquid such as molten cast iron of more or less irregularshape Will progressively te; .d to a shape having a circularcross-section. Ifthe stream of liquid-instead of falling vertically,flows through a channel inclined to the vertical, its acceleration ismodiiied by the trictional resistance encountered and by such energy asis lost in. changes of direction and, as the guiding channel vapproachesthe horizontal, ac'- celeration may @ease to occur so that under someconditions the rate of flow of the liquid may be retarded and, again,the forces actingupon a falling stream of liquid to bring it toacircular section are, of course, mitigated where the liquid flows overan inclined surface, Practical consideratidns affecting the constructionofi a centrifugal casting apparatus are such that it is not alwayspractical to locate the ladle with respect to the mold and trough atwhat might seem from theoretical considerations to be its properposition. The height of the ladle must be such as will bring about asatisfactory rate of flow through the trough and a ksatisfactory outflowof the molten metal through the delivery spout at the end of the trough.Again, the chute channel must be wide enough to 'receive the fallingstream of 4o molten iron l`delivered 13A the ladle at its upper endWhile-at its lower end it 'should have the breadth ofv thechannerpmvided in the trough and, as heretofore constructed. theliability of the metal flowing through the chute to throw out sprays ofmolten metal and to bring about so turbulent a ow as will sometimescause metal to be thrown over the sides' of the trough and to bringabout splashing of the metal as it contacts withthe mold is, we havefound, due to the facts, first, thatthe longitudinal contour of thechute chanelhasbeen such as to eiect unduly abrupt changes in thedirection of' ow of the molten iron, and, second, that the convergenceof the side walls of the chute channel has not been g5 top to receivewithin its side walls the stream of metal delivered by the ladle andmust be narrowed at its delivery end to a breadth substantially thesame' as that of the channel in the trough into which the chute deliversthe metal stream, we have found itpracticable in all cases topractically eliminate the danger of forming a spray of metal issuingfrom the surface of the metal stream and to so greatly reduce theturbulence in the stream as to eliminate the spraying of metal from thechute, the occurrence of splashes from the sides of the trough and theoccurrence of splashes when the metal contacts with the mold by formingthe chute with a bottom longitudinal contour of such character that ator about the point where the metal rst contacts with the chute theinclination of the chute to the vertical would not exceed and whichreceiving surface is continued as a substantially geometric curve drawnbetween a tangent of the 30 same angular inclination to the vertical asthat of the receiving portion of the chute and a tangent. at or near thedelivery end of the chute, forming a slight angle with the horizontaland lying substantially parallel to the trough. By preference the curveshould be of such a char- 0 and 20.

acter that 'its tangent at its upper end is considerably less than 30and it is generally practicable to use a curve the upper tangent ofwhich will form an angle with the vertical of between F By preferencethe geometric curve is continued to the point of impact of the fallingstream of metal but as it is desirable that the curve should ilattenout, so to speak, as it approaches its lower tangent it is desirablethat the i5 length of its upper tangent between its point of Y contactwith the curve and its point of inter- *lsection with the lower tangentshould be shorter than the length of the lower tangent between its pointof contact with the upper tangent and its 150l point of contact with thecurve.

While any geometric curvature of the chute conforming to the conditionsabove indicated will give improved results, we have foundthat the mosteffective and satisfactory curve is that of a parabola which, especiallywhere the curvature progressively diminishes as the delivery end of thechute is approached, will, we have found, bring about a ilow of themolten metal with minirum turbulence and minimum tendency Lto throw outa spray of metal from the surface.

With regard to the contour of the side walls of the chute channel, thesewalls must be spaced apart at the line of impact of the metal fallingfrqm the chute by a distance equal to the breadth of the stream of metalwhile at the delivery end of the .chute and preferably somewhat inadvance of the delivery end, the breadth of the channel between the sidewalls must be essentially the sameas the `breadth of the channelin thetrough into which tliemetal is delivered. The

vertical height of the chute must be auch as, in view of the generalinclination and shape of the channel formed in the chute, will result inimpartingto the stream of molten metal at the delivery end of the chutea velocity'which will carry the stream of metal into and through thetrough at a rate of speed which will keep the level of the stream in thetrough suiliciently below the top edges of the channel to avoid the riskof the metal spilling over the sides of the trough and, at the sametime, to secure the delivery of the metal to the spout at the end of thetrough at such moderate velocity and absence of turbulence as will notbring about splashing of the metal as it comes in contact with the mold.It will be understood, of course, that the ladle delivering the moltenmetal to the chute and its actuating mechanism should be of such acharacter that it is adapted to deliver its contents at an even rate, isnecessarily so located and constructed that its pouring lip will, underall conditions, lie at a somewhat higher level than that portion of thechute to which it delivers a stream of metal so that the metal stream asit ilrst contacts with the chute is already moving with a velocitydetermined by the rate of pouring and the height of its fall from thelip of the ladle; this involves that the breadth of the chute at thepoint of contact should be somewhat less than the length of the lip and,consequently, that the forces we have mentioned 4tending to diminish thecross-sectional area of the stream and change its form will haveresulted, at the time the stream contacts with the chute, in somewhatnarrowing the breadth of the stream but the distance through which themetal falls freely from the ladle is yin practice made as short aspracticable and the chute itself is relied upon to effect in great partthe necessary narrowing of the breadth of the stream to a breadthcorresponding to the breadth of the channel in the trough and theproblem which confronted us with regard to the contour of the side wallsof the trough channel was to give themvsuch a shape as would effect thenecessary narrowing of the stream of metal under conditions which wouldnot bring about a spraying of the metal or undue turbulence in theflowing stream. In considering this problem we had to take into accountthat in casting pipes of diierent sizes, it is necessary to use chutesof varying vertical height with, of course, corresponding changes in thevertical height of the ladle above the level of th trough and thatpractical considerations do not always make it possible to use chutes ofa horizontal length which stream would narrow in falling freely througha a vertical distance equal to the length of the chute between the pointwhere the metal contacts with it and the point where it is deliveredwould aii'ect the narrowing of the stream with but little tendency toproduce turbulence but, as we have explained, the breadth of the streamat the delivery end of the chute must be practically the vsame as thatof the channel into .which the metal is delivered and the breadth of thestream delivered by the ladle to the upper part of the chute cannot bearbitrarily limited though in many cases it is n practicable to soconstruct the ladle and its pournig 11p that it' will denver to Athechute a stream of metal the breadth of which at the point of impact willnot exceed eight times the breadth of the stream at the delivery end ofthe chute and we have found it highly advantageous that this ratiosliould not be exceeded and, where practicable, should be less. In mostcases it is not practicable to give the chute a horizontal length suchv'as would betheoretically desirable but we have discovered that inallcases a reasonably satisfactory nonturbulent ow of the molten metalthrough and from the chute can be secured by giving to the side wallso'f the channel in the chute lthe form of converging geometric curvesupon.

which the trace of the center line ofv the chute channel, when developedto its true length on a horizontal plane, will have a curvature at theupper end of the curve corresponding approximately to the point ofimpact of the metal and will have a tangent forming an angle with thecenter line of the chute not to exceed 30 and which, at the delivery endof the chute, will have a tangent substantially parallel to the centerline of the chute. By preference, and when compatible with theangularity of the upper tangent to the center line of the'chute, thetangent lines their point of intersection with each other/'should beapproximately of the same length and while improved results areobtainable with practically all curves drawn in accordance with theprovisions above given, we have vfound that the most effective curvaturefor the side walls is that of a parabola and, in speaking of thecurvature of the side walls, it should be understood that we arespeaking of the curvature of the trace of the center line of the chuteupon the surface of the side walls as such trace is developed4 on ahorizontal plane as this is the curvature of the side wall which isactually followed by the ilowing metal y and this is the improvedconstruction as effecting 'form of the-surface of the chute, and, forthe best resuus, both the bottom and side` walls of the chute channelshould be given the forms which we have indicated and, again, we wouldpoint out that while in most case's it is advantageous that vthe curvesof the center line of the chute and of its side walls should continue toapproximate the delivery end of the chute, our invention can beadvantageously used with chutes in which the bottom curvatureof thechute channel merges into a straight line and in which the,side walls,to a corresponding distance, may run ,parallel to each other beforemerging into curves which we have described. l With regard to the formof the chute above the line of impact of the metal falling upon it,this, it will be understood, isimmaterial so far as our invention isconcerned and will be, determined by practical considerations involvingthe necessary clearance of the ladle lip. y f

It will, of course, be understood that in describing the curvature ofthecenterline and side walls of the chute as geometrical curves we are notto bve understood as limiting ourselves to truly mathematic curves assuch perfection of curvature is hardly practical of attainment butcurves ap-Y proximating the curvatures which we have de-l scribed areentirely practicable and can follow within the scope of our invention.

As ,examples of .chutes -which we have designed and successfully used inpractice, we will give the following:

Example one Height of chute, 161/2 inches; horizontal length of chute,43 inches; distance between side walls at line of impact of metal,1&inches; breadth of channel at delivery end of chute, '3 inches; centervline of channel, a parabolic curve drawn be- .tween a tangent at itsupper end forming an angle of 15 with the vertical and a tangent at itslower end forming an angle of 31/ with the horizontah, curvature of sidewalls along the trace of the center line upon lsaid walls as developedin a horizontal plane; parabolic curves drawn between the tangent at theupper end of the chute forming an angle of 18 with the center line ofthe chute and a tangent at the delivery end of the 'chute lying parallelto the center line.

Errample two Height of chute, 231A inches; horizontal length of chute,361/4 inches; distance between side walls at line of impact of metal, 12inches; breadth of channel atdelivery end of chute, 21/2 inches; centerline of channel, a parabolic curve drawn be'' tween a tangent at itsupper end forming an angle of 30 with the vertical and a tangent at itslower end forming an angle of 3 with the horizontal; curvature of sidewalls along the trace of the center line upon said walls as developed ina horizontal plane; parabolic curves drawn between the tangent at theupper end of the chute forming an angle of 13 with the center line ofthe chute and a tangent at the delivery end of the chute lying parallelto the center line.

Example three Height of chutei 181/2 inches; horizontal length of chute,531/2 inches; distance between side walls at liney of impact of metal,18 inches; breadth of channel at delivery end of chute, 3 inches; centerline of channel, a parabolic curve drawn between a tangent at itsiupperend forming an' angle of 20 with the vertical and a tangent at its lowerend forming an angle of 2 with the horizontal; curvature of side wallsalong the. trace of the center line upon side walls as developed in ahorizontal plane; parabolic curves drawn between the tangent at theupper end of the chute forming'an angle of 15 with the centerline of thechute and a tangent at the delivery end of the'chute lying parallel tothe being provided for nearer the point where the trough enters the moldin the more advanced position of the mold and the chute has beensupported in and by the trough at its lower end and by adjusting screwslocated at the top of the ladle supporting structure and the chute hasbeen kept in abutting contact with the lining blocks with which thetrough is provided by a .spring located in the rear portion ofthe troughand abutting against the shoulder formed on the chute and lying in thetrough. It is impracticable in these older constructions to form a chutewith the channels substantially conforming to our improved constructionnor do the means heretofore employed for supporting lthe chute reliablysecure an accurate abutment of the delivery end of the trough againstthe 1ining blocks and to provide a structure suitable for use inconnection with our improved chutes and a more reliable way of securingand maintaining a proper alignment of the chute with the lining blocksof the trough we construct the trough so that it'will not extend forwardbeneath the chute to a greater extent than is necessary to afford a seatfor the delivery end of the chute and secure to the front end of thetrough a forwardly extending supporting structure preferably formed bybeams firmly secured to the sides of the trough the side walls of whichstructure are so spaced apart as to alfford clearance for the portionsof the chute structure which may extend between them and which are,moreover, so spaced apart as to afford a good supporting base upon whichlugs or feet extending down from the upper and wider portions of thechute may rest so that the chute is supported entirely upon the frontend of the trough and upon the sidewalls of the troughv supportingstructure. Our new construction fur.

ther involves the provision of a guideway supported by the troughsupporting structure upon which are slidingly supported and guidedspring caps, one abutting against a. shoulder formed on thechute and theother against a suitable support and holding between them a springadjusted to maintain the delivery end of the chute in contact with thelining blocks Vof `the trough and,

to protect the spring and spring supporting structure from being fouledby molten metal or Vfoundry dirt, we secure to the side walls of thetrough supporting structure a cover plateextending over the springstructure and our improvements will perhaps be better understood asfurther described in connection with the drawings in which Figure 1 isan elevation of a centrifugal pipe casting machine embodying ourimprovements taken on a central longitudinal section.

Figure 2 is a fragmentary plan views., of the chute, the end of thetrough on which it is supported and ia portion of the trough supportingstructure, shown on a larger scale than Fig. 1.

Figure 3 is a sectional elevation of apart of the structure shownin Fig.1, on a large` scale.

Figure 4 is across-sectional view on the line 4 4 of Fig. 3.'

Figure 5 is an elevation viewed from'the left of the chute and troughsupporting structure.

Figure 6 is a cross-sectional View on the line l-6 of Fig. 3.".

of laying out the curves of the side walls of the chute in what webelieve to be their' most effective curvature, and

Figure 18 is'a diagram illustrating an effective way of laying out thecurve of the center line of the chute in what we believe to be its mosteiiective curvature.

A indicates the framing forming the base of the pipe casting machine, A1an elevated structure or tower supporting the ladle indicated at A2, a2indicating the lip oi' the ladle. Mechanism for tipping the ladle isindicated at As and, as it forms .no part of our invention, need not bedescribed in detail. A* indicates the carriage supported on wheels a4and supporting a water box A5 traversed by a rotatable mold A to whichrotary motion is by a mowr A" and gears A. Reciprocating motion is givento the carriage by a cylinder and piston as indicated at A9. In all ofthe above noted featureshthe apparatus is of usual construction. Bindicates the trough structure made up, as shown, of an outer casing B1which is divided into a central or trough structure and watercirculating chambers B5, B3, by partitions indicated at B4, B4. B5, B5,indicate water supply -pipes for introducing water into the watercirculating chambers, B5, B5, indicating lining blocks in the troughsection through which is formed 'the y trough channel and B" indicatesthe terminal or delivery spout of the trough. In all ofy the above notedfeatures the trough structure is oi well known construction but asheretofore constructed the described trough structure, with theexception oi' the lining blocks, is continued'iorwardly, that is tosay,U toward the structure supporting the ladle to a support, whereas inour present construction the trough is continued forwardly only to asufllcient distance to afford a seat and support for the end of thechute -to be described.v

In our new construction, supporting means for the trough are attached toits forward end and formed with side walls spaced apart by a sufilcientdistance, greater'than that of the trough proper, to aiiord clearance tothe portions of the chute which extend between the walls and a rmsupport for the front or upper portion of the justing screws, indicatedat D1, are provided for the proper alignment of the trough.

Returning to the structure for the support of the front end of thetrough, C4, C4, are plates se- I.

cured to the lower sides of the beams C, C, and supporting in turn acentral longitudinal guideway C5, indicated as a channel beam. Supportedonwand guided by this channel beam are spring caps C5, C5, one abuttingagainst a shoulder on the chute as will be described and the otherabutting against an adjusting screw indicated at C". C indicates aspring, the ends oi' winch are engaged in the spring caps, and C is iacover plate extending between the beams C. C. f and4 serving as aprotection to the spring structure described. (n v x* E indicates ournew chute construction, the chute being .provided to receive the metalas it is poured out from the ladle and deliver-it to the front end ofthe trough. Chutes for this -purpo'sefhave heretofore been in use andhave kbeen prvided with side walls spaced apart at their upper ends by adistance greater than the .y Y. of sulcient volume to supply the moldand bring about the production of a pipe o! the desired the developmentof a chute which will impart the necessary velocity to the stream ofmetal passing through it and the necessary change in cross sectionalform with a minimum degree of turbulence in the flowing stream of metaland with .this object in view we form the bottom of the chute channel sothat approximately at the point indicated at E1 where the falling streamof metal first contacts with the chute it will form an angle of not morethan 30 with the vertical, a smaller angle being preferable and wecontinue the bottom of the-chute channel, thecenter line of which isindicated at E2, as a geometric curve merging into the receiving surfaceat the top of the chute and having at its upper end a tangent lying inthe receiving face of the channel and having, of course, the sameangular inclination with the vertical and another tangent at thedelivery end 'of the chute which is approximately horizontal andpreferably forming' only such angle with the horizontal as is the casewith the channel in the trough to which the chute delivers its metal.The curved surface of the chute channel, as is indicated at E3, andwhich preferably extends from the point of impactof the metal, indicatedat E1, has a continuous curve to the delivery end of the chute and, forthe best results, this curve should be a parabolic curve, or curvedsegment, although other geometric curves filling the same condition asto tangency may be used with advantage as compared'with previously ex'isting contours .of the chute surface. The essential conditions to havein view are, that the metal falling fromthe ladle should not strike achute surface of a greater angularity to the vertical' tangent to whichat the delivery end of the chute f should lie practically parallel tothe channel in the trough. It is, however, decidedly advantageous thatthe curvature o-f the chute channel as it approaches the delivery end ofthe chute should be of progressively decreasing curvature and this,where other conditions make it practicable, should be provided forbyr'so constructing the chute that the tangent line from the upper endof the curve to its point of intersection with the tangent line from thelower end of the curve should be shorter than the length of the tangentline from thelower end of the curve to the point of intersection. InFig. 18, we have illustrated the laying out of the center line of thechute in a parabolic curve. Thebroken line F indicates the vertical'height of the chute and the partly broken and partly fulll line F1 andFG, of which the full line portion F3 is a tangent line, ,indicatevthehorizontal length of the chute. The tangent to the upper end of thecurve is indicated at yF3 and the tangent to .the lower end of the curveis indicated at F3, their point of intersection, being indicated at F4.In laying off the parabolic curve between these two tangents, aconvenient and satisfactory plan is to divide the two tangent lines F2and F3 into the same number of divisions as indicated on the .uppertangent line at f1,

`g1, g2, g3, g4, g5, g6 and g", then drawing straight lines, asindicated, from f1 to g1, from -P to g. etc. These lines willV formtangents of a parabolic curve and facilitate the laying out of such acurve for the use of the pattern makers.

The side walls of the chute channel which areI indicated at E4, E4, arenecessarilyspaced apart at their upper ends byl a distance slightlygreater than the breadth of the stream of metal falling upon the chutefrom the ladle and necessarily converge so that at the delivery end ofthe chute they are distant from each other by approximately the samedistance as the' width of the trough channel. The function of the sidewalls is to contract the stream of molten metal which is, for thegreater part of its passage through the chute, moving with acceleratingvelocity and consequently with progressive contraction of itscross-sectional area. 'I'he forces bf molecular attraction and surfacetension which tend to bring a'falling stream of liquidof irregular shapeto a form having a circular cross-section are also, to some extent,operative even when the liquid is owing over an inclined surfacealthough opposed in such a case by the weight of the metal tending tospread it out over its supporting surface. Our investigations have ledus tod believe that a side wall construction in which the walls wouldconverge toward each other approximately as the sides of the fallingstream would converge in ifalling through a distance approximating thevertical distance between point of irst contact and point of delivery,would bring abouta narrowing of the stream with the least possibleturbulence but in practice the height and length of the chute channelare determined by other considerations and in developing a constructionof the side walls of the chute which will in prac- 'tice produce aminimum turbulence in the flow of the molten iron we have had to takeall practical considerations into account, inclusive of such changes inthe height and length of chutes as are found necessary in the casting ofpipes of different diameters and varying wall thickness as well as theadapting of our improved chutes for substitution in pipe castingmachinery already existent. The essential curvature of the side walls isof that portion of the walls with which the metal 'actually contacts inthe passage through the chute channel, that is to say, of portions ofthe side walls lying approximately opposite to the center line of thechute and following the curvature of said centerline, said portions ofthe side walls having, so to speak, a double curvature, that is to say,curving downward from the upper portion of the chute to its delivery endand inward toward the center line of the chute and we have found that aneffective and satisfactory curvature of the side walls should be suchthat the trace of their surfaces upon the bottom surface 'of the chutewhen developed to its true length upon a horizontal plane, will form ageometric curve, preferably a parabolic curve lying between tangents,the upper Aone of which will .form an angle of not to exceed 30 with thedeveloped center line of the chute and the lower.

one of which, at the delivery end of the chute, will be essentiallyparallel with the center line.

.Where practicable the length of the tangent ture of the side walls ofthe chute with parabolic curves along the line of fiow ofthe metalwhereit contacts with the side walls. In this diagram, E, E3, representthe development of the centerline of the chute to its true length as astraight line between the point of first contact and point of delivery.At the upper end of this line we erect a right angle line indicated at Hand of a length equal to half the breadth of the chute channel at orabout the point of contact of the molten metal and at the lower end ofthe developed center line corresponding to the delivery end of the chutewe erect a right angle line H1 of a length equal to half the breadth ofthe chute channel at this point. From the end of the line H, whichcorresponds approximately to thepoint on the sidawall where the metalstream from the ladle iirstcontacts with it, we draw a line H2 formingan angle of not more than 30 with the center line E, E3, and from theend of the line H1 we draw a line H3 parallel to the center line and wethen lay out a geometric curve H* of such a character that the lines H2.and H3 will form tangents to the curve at the points on the lines H andHl from which such tangent lines are drawn ani-subject to the statedlimitation as to the angle which the tangent line H2 must form with thecenter line of the chute, we draw the lines H2 and H3 at such angularitywith each other that they will intersect, as indicated at H5, at avpoint equi-distant from the two points of tangency to which the tangentsare drawn. The curvature of the developed trace of the center line uponthe side walls is preferably that of a parabolic curve which isconveniently drawn, as indicated in Fig. 17, by dividing the tangent H2into any desired number of equal parts, as indicated at h1, h2, h3, h4,115,111.6 and h", and dividing the tangent line H3 into the same numberof equalparts as indicated at i1, i3, 3, #,15, i and i", and thendrawing a series of straight lines connecting the division points h1 andi1, h3 and i3, etc., which lines will form tangents to a parabolic curveand practically facilitate the laying out of such a curve for theuse o1'the pattern maker.

In referring to other geometric curves as possible substitutes forparabolic curves in the center line of the chute and in the contour ofthe side walls as developed we have in mind such curves as can be laidout between intersecting tangents and while it is true that such curves,other than parabolic curves, will give improved results as compared withthe contour'lines of chutes as previously used in centrifugal pipecasting machines, we have found that the parabolic curves are decidedlybetter than others as bringing about the ow of molten metal through thechute with the minimum of turbulence.

The delivery end of the chute indicated at E5 is formed, as we havestated, with its channel conformed in cross-section to the shape of thechannel formed through the lining blocks B of the trough and with itsouter dimensions conformed to-the shape of the` front end of the trough.B in which this delivery end 0! 4the chute is supported( with itsextreme end abutting against the front lining block of the trough and itis important that the fitting of the end of the chute against the frontlining block should be reasonably accurate and not afrectedby ad'justments o'f the trough and to secure an accurate and permanentalignment of the chute with the trough we provide the front or upper endof the chute with downwardly extending supporting legs as indicated atE, E', which enses@ IJld rest upon the tops of the side walls of thesupporting structure C, thereby insuring in all adjustments of thetrough and its supporting structure that the proper alignment of thechute and trough shall be maintained.

On the underside of the chute we provide a spring abutment shoulderindicated at E", against which the rear spring cap C6 abuts and thenecessary compression is given to the spring C3 by shifting the frontspring cap C6 by the adjusting screw C7.

The assembly and operation of our improved machine will be clear tothose skilled in the art from the above description and need not, webelieve, be further detailed.

Having now described our invention, what we claim as new and desire tosecure by Letters Patent, is:

1. In centrifugal pipe casting apparatus comprising a rotatable mold, aconduit for the delivery of molten metal extending into the mold, aladle adapted to contain and deliver molten metal located in front ofand at a higher level than the mold, the combination therewith of aninclined chute adapted to receive the metal from the ladle and deliverit to the conduit entering the Infeld, which chute is formed with abottom contour which, at approximately the point where the metal fromthe ladle first contacts with the chute,is inclined to the vertical atan angle not exceeding 30 and which is continued as a geometric curve ofprogressively decreasing curvature having at its upper end a tangentcoincid-l ing in angular inclination with the angular inclination of thechute at the point of impact of the metal and having at the lower end ofthe curve an approximately horizontal tangent.

2. In centrifugal pipe casting apparatus comprising a rotatable mold, aconduit for the delivery of molten metal extending into the mold, aladle adapted to contain and deliverv molten metal located in front ofany at a higher level than the mold, the combination therewith of aninclined chute adapted to receive the metal from the ladle and deliverit to the conduit entering the mold, which chute is formed with a bottomcontour which, at approximately the point where the metal from the ladlefirst contacts with the chute, is inclined to the vertical at an anglenot exceeding 30 and which is continued as a substantially paraboliccurve drawn between a tangent of the same angular inclination to thevertical as that of the receiving portion of the chute and anapproximately horizontal tangent, at or near the delivery end of thechute.

3. Apparatus'as called for in claim 2, in which the parabolic curvatureofc the bottom contour of the chute is of such a character that thelength of the tangent drawn from the upper end of the parabolic curve toa point of intersection with the tangent line drawn from thev lower endof the parabolic curve will be less than that of the tangent line drawnfrom 'the lower point oi.' the curve to the point of intersection.

4.' Apparatus as called for in claim 2, in which the parabolic bottomcurvature of the chute is continued at its upper end to approximatelythe point where the metal from the ladle iirst contacts with the chute.

5. In centrifugal pipe casting apparatus comprising a rotatable mold. aconduit for the delivery of molten-'metal extending into the mold, aladle ladapted to contain and deliver molten metal located in front ofand at a higher level than the niold, the combination therewith ot aninclined chute adapted to receive the metal from the ladle anddeliver itto the conduit entering the mold, which chute is formed with a bottomcontour which, at approximately the point where the metal from the ladlerst contacts with the chute, is inclined to the-vertical at an angle notexceedingv30 and which is continued as a geometric curve having atitsupper end a 'tangent coinciding in angular inclination with the anguiarinclination of the chute at the point of impact of the metal and havingat the lower end of the curve an approximately horizontal tangent,further characterized in that the chute is vprovided with side wallswhich, at the point where the metal frointhe ladle contacts with thechute, are spaced apart by approximately the breadth of the metal streamfalling'from the lip of the ladle and at the 'delivery end of thechuteby the breadth of the stream of metal which the chute is designedto deliver and which side walls progressively converge in `relativelyconvex curves of such a character that the trace. of the bottom line ofthe chute thereupon will, when developed to its true length upon ahorizontal plane, form a geometric curve drawn between a tangent to theupper end of the curve forming an angle of not more than 30 with thecenterline of the chute and a tangent to the lower end of the curvelying parallel to said center line.

6. ,In centrifugal pipe casting apparatus comprising a rotatable mold, aconduit for the delivery of molten metal extending into the mold, aladle adapted to contain and ldeliver molten metal located infront ofand at a higher level than the mold, the combination therewith of achute adapted to receive the metal from the y ladle and deliver it tothe conduit entering the mold, which chute is formed with a downwardlyinclined channel for the passage of molten metal having side wallswhich, at the point where the metal from the ladle contacts with thechute, are spaced apart by a distance not materially greater than thebreadth of the stream yof molten metal delivered from the lip of theladle at the time it contacts with the chute and which,

at or near the delivery end of the chute, are spaced apart by a`distance substantially the same as the breadth of the conduit intowhich -the chute delivers the molten metal, each of said converging sidewalls having a surface contour which passes through a point at oradjacent to that at which the metal of the ladle first contacts with theside wall andl throughv a point at the lower end of the chute/which isdistant from the center line of the chute by half its width. saidsurface contour'being such that the trace formed by it upon the surfacecontour of the i bottom of the chute, when developed to its true length,will be a curve, a tangent' to which at the point where the metal rstcontacts with the wall of the chute will form an angle with the centerline of the chute of not more than 30 and at the point at the lower endof the wall will have a tangent essentially parallel to the center line.

, .'I. In fentrifugal pipe casting apparatus comprising a rotatablemold, a conduit for the delivery of molten metal extending into themold, aladle adapted to contain and deliver molten metal located infront of and at 'a higher level than the mold, the combination therewithof. a chute adapted to receive the metal from .the ladle and deliver itto theconduit entering the mold, which chute is ormedwith a downwardlyinclined channel for the passage cf molten metal having side wallswhich, at the point where the metal from the ladle contacts with thechute, are spaced apart by a distance not materially greater than thebreadth of the stream of molten metal delivered from the-lip of theladle at the time it contacts with the chute and which, at or near thedelivery end of the chute, are spaced apart by a distance substantiallythe same as the breadth of the conduit into which the chute delivers themolten metal, each of said converging side walls having a surfacecontour which passes through a point at or adjacent to that at which themetal of the ladle irst contacts with the side wall and throughapoint atthe lower end of the chute which is distant from the center line of thechute by half its width, said surface contour being such that the traceformed by it upon the surface contour of the bottom of the chute, whendeveloped to its true length, will be a curve, a tangent to which at thepoint where the metal rst contacts with the wall of the chute will forman angle with the center line of the chute of` not more than and at thepoint at the lower end of the wall will have a tangent essentiallyparallel to the center line, said side wall curvature being `furthercharacterized in that the tangents from the upperl and lower ends of thecurved wall intersect each other at a point approximately equi-distantfrom the two points of tangency.

8. In centrifugal pipecasting apparatuscomprising a rotatable mold, aconduit for the delivery of molten metal extending into the mold, aladle adapted to contain and deliver molten metal located in front ofand at a higher level than the mold, the combination therewith of achute adapted to receive the metal from the ladle and i nel for thepassage of molten metal having side walls which, at the point where themetal from the ladle contacts with lthe chute, are spacedapartbyadistance not materially greater than the breadth of the streamof molten metal delivered from the lip of the ladle at the time itcontacts with the chute and which, at or near the delivery end of thechute, are spaced apart by a distance substantially the same as thebreadth of the conduit into which the chute delivers the molten metal,each of said converging side walls having a surface contour which passesthrough a point at or adjacent to that at which the metal of the ladlerst contacts with the side wall and through a point at the lower end ofthe chute which is distant from the center line of the chute by half itswidth, said surface contour being such that the trace'formed by it uponthe surface contour of the bottom of the chute, when developed to itstrue length on a horizontal plane, will be a subf stantially paraboliccurve, a tangent to which at the point where the metal rst contacts withthe. wall of the chute will form an angle with the center line ofthechute ofnot morethan 30 and at the point aty the lower end of the Wallwill have a'tangent essentially parallel to the center line. D

9. In centrifugal pipe casting apparatus comprising a rotatable mold, aconduit for thedelivery of molten metal extending into the mold,

a ladle' adapted to contain and deliver molten inclined channel for thepassage of molten metal having side walls which, at the point where themetal from the ladle contacts with the chute, are spaced apart by adistance not materially greater than the breadth of the stream of moltenmetal delivered from the lip of the ladle at the time it contactsgwiththe chute and which, at or near the delivery end of the chute, arespaced apart by a distance substantially the same as the breadth of theconduit into which the chute delivers the molten metal, each of saidconverging side walls having a surface contour which passes through apoint at or adjacent to that at which the metal of the ladle firstcontacts with the side wall and through a point at the lower end of thechute which is distant from the cen ter line of the chute by half itswidth, said surface contour being such that the trace formed by it uponthe `surface contour of the bottom of the chute,when developed to itstrue length on a horizontal plane will be a substantially paraboliccurve, a tangent to which at the point where the metal first contactswith the wall of the chute will form an angle with the center line ofthe chute of not ore than 30 and at the point at the lower end o thewall will have a tangent essentially parallel to the center line, saidside wall curvature being further characterized in that the tangentsfrom the upper and lower ends of the curved wall will intersect ealchother at a point approximately equi-distant from the two points oftangency.

10. In centrifugal pipe casting apparatus comprising a rotatable mold, aconduit for the delivery of molten metal extending into the mold, aladle adapted to contain and deliver molten metal located in front ofand at a higher level than the mold, the combination therewith of achute adapted to receive the metal from the ladle and deliver it to theconduit entering the mold, which chute is formed with a bottom contourwhich, at aproximately the point where the metal from the ladleflrst'contacts with the chute, is inclined to the vertical at an anglenot exceeding 30 and which is continued as a substantially parabolicIcurve drawn between a tangent of the same angular inclination to thevertical as that of the receiving portion of the chute and a tangent, ator near the delivery end of the chute, forming a slight angle with thehorizontal, said chute being further characterized in that the channelformed therein for the passage of molten metal is formed with side wallswhich, at the point where the metal from the ladle contacts with thechute, are spaced apart by a distance not materially greater than thewidth of the stream of molten metal at the time it contacts with thechute and which, at or near the delivery end of the chute. are spacedapart by a distance sub- 'stantially the same as the breadth of theconduit into which the chute delivers the molten metal, each of saidconverging side walls having a surface contour which passes through apoint at or adjacent to that at which the metal of the ladle firstcontacts with the side wall and through a point at the lower end of thechute which is distant from the center line of the chute by half itswidth. said surface contour being such that the trace formed by it uponthe surface contour of the bottom of the chute, when developed to itstrue length. will be a parabolic curve, a tangent to which at the pointwhere the metal first' contacts with the wall of the chute will form anangle with the center line of the chute of not more than 30 and at thepoint at the lower end of the wall will have a tangent essentiallyparallel tothe center line, said tangents in the development subject tothe angular limitation intersecting each otherat a point approximatelyequi-distant from the two points on the curve to which' the tangents aredrawn.

l1. In centrifugal pipe casting apparatus comprising a trough or runnerhaving a delivery spout at its end, a relatively reciprocablecentrifugal mold, a ladle for containing and delivering molten metallocated above and in front of the mold and trough, the combinationtherewith of a chute adapted to receive the metal from the ladle anddeliver it to the trough and through the trough to the mold, having achannel which at its delivery end conforms to the shape of the channelin the trough, which chute is formed with a bottom contour which, atapproximately the! point where the metal from the ladle first contactswith the chute, is Ainclined to the verticafat an angle not exceeding 30and which is continued as a substantially parabolic curve drawn betweena tangent of the same angular inclination to the vertical as that of thereceiving portion oi' the chute and a tangent at the lower end of thechute ,substantiallytparallel to the trough.

12. In centrifugal pipe casting apparatus comprising a trough or runnerhaving a delivery spout at its end, a relatively reciprocablecentrifugal mold, a ladle for 'containing and delivering molten metallocated above and in front of the mold and trough; the combinationtherewith of a chute adapted to receive the metal from .the ladle anddeliver it to the trough and through the trough to the'mold, which chuteis formed with a downwardly inclined channel for the passage of moltenmetal having side walls which, at the point where the metal from theladle contacts with the chute, are spaced apart by a distance notmaterially greater than the Width of the stream of molten metal at thetime it contacts with the chute and which, at the delivery end of thechute, are spaced apart by a distance substantially the same as thebreadth of the channel in the trough into which the chute delivers themolten metal, each of said converging side walls having a surfacecontour vwhich passes through a point at or adjacent to that atV whichthe metal of the ladle first contacts with the side wall and through apoint at the lower end of the chute which is distant from the centerline of the chute by half its width, said surface contour being suchthat the trace formed by it upon the surface contour of the bottom ofthe chute, when developed to its true length, will be a parabolic curve,a tangent to which vat thev point where the metal first contacts withthe wall of the chute will form an angle with the center line of thechute of not more than 30 and at the point at the lower end of thel wallwill have a tangent essentially parallel to the center line, saidtangente in the development subject to the angular limitationintersecting 'each other at a point approximately equi-distant from thetwo points on the curve to which the tangents are drawn. A

13. In centrifugal pipe casting apparatus comprising a trough or runnerhaving a delivery spout at its end, a relatively reciprocablecentrifusal mold, s. ladle for containing and delivering molten metallocated above and in front of the mold and trough, the combinationtherewith of a chute adapted to receive the metal from the ladle anddeliver it to the trough and through the trough to the mold, which chuteis formed with a bottom contour which, at approximately the point wherethe metal from the ladle iirst contacts with the chute, is inclined' tothe vertical at an angle not exceeding 30 and which is continued as asubstantially parabolic curve drawn between a tangent of the sameangular inclination to the vertical as that of the receiving portion ofthe chute and a tangent, at or near the delivery end of the chute,forming a slight angle with the horizontal, said chute being furthercharacterized in that the channel formed therein for the passage ofmolten metal is formed with side walls which, at the point where themetal from the ladle contacts with the chute, are spaced apart by adistance not materially greater than the width of the stream of moltenmetalat the time it contacts with the chute and which, at the deliveryend of the chute, are spaced apart by a distance substantially the sameas the breadth of the channel in the trough into which the chutedelivers the molten metal. each of said `converging side walls having asurface contour which passes through a point at or adiacent to that atwhich the metal of the ladle iirst contacts with the side wall andthrough a point at the lower end of the chute which is distant from thecenter line of the chute by half its width, said surface contour beingsuch that the trace formed by it upon the surface contour of the bottomof the chute, when developed to its true length, will be a paraboliccurve, a tangent to which at lthe point where the metal first contactswith the wall of the chute will form an angle with the center line ofthe chute of not more than 30 and at the point at the lower end of thewall will have a tangent essentially parallel to the center line, saidtangente in the development subject to the angular limitationintersecting each other at a point approximately equi-distant from thetwo points on the curve to which the tangents are drawn.

14. In centrifugal pipe casting apparatus comprising a trough or runnerhaving .a delivery spout at its end, a relatively reclprocablecentrifugal mold, a ladle for containing and delivering molten metallocated above and in front of the mold and trough, the combinationtherewith of a vchutey adapted to receive the metal from the ladle anddeliver it to the trough and through the trough to the mold, having achannel which, at its delivery end, conforms to the shape of the channelin the trough, which chute is formed with a bottom contour which,atapproximately the point wherethe metal from the ladle rst contactswith the chute, is inclined to the vertical at an angle not exceeding 30and which is continued as' a substantially geometric curve drawn betweena tangent of the same angular inclination to the vertical as that'of thereceiving portion of the chute and a tangent at the lower end of thechute substantially parallel to the trough, and further characterized inthat the delivery end of the chute entersvand is supported by the frontend of the trough and the trough is provided with a forwardly extendingangularly adjustable supporting structure having side walls which attheir upper portions are spaced apart by a greater distance than that ofthe side walls of the trough structure and so as to give clearance tosuch portions of the chute as may extend between them. I

l5. In centrifugal pipe casting apparatus comprising a trough or runnerhaving a delivery spout at its end, a relatively reciprocablecentrifugal mold, a ladle for containing and delivering molten metallocated above and in front of the mold and trough and an inclined chutear-L l ranged to receive the metal from the ladle and deliver it to thetrough, the improved construction in which the delivery end of the chuteenters and is supported by the front end of the trough and the trough isprovided with a forwardly extending angularly adjustable supportingstructure having side walls which at their upper portions are spacedapart by a greater distance than that of theside walls of the troughstructure and so as to give clearance to such portions of the chute asmay extend between them and in which the chute is supported at itsdelivery end by the trough and at its receiving end by the side walls ofthe supporting structure.

16. In a centrifugal pipe casting apparatus comprising a rotable moldrelatively retractable which enters the trough and abuts against the 40lining blocks of the trough and the upper end of which is located toreceive molten metal from the ladle. the improvement which consists lnso constructing the trough that its front end does not extendsubstantially farther beneath the chute than that portion of the lowerend of the chute which lies in the front end of the trough, combiningwith the front end of the trough a forwardly extending angularlyadjustable supporting structure having side walls spaced apart by agreater distance than that separating the side walls and that portion ofthe trough structure in which the end of the chute is supported so as toafford increased clearance for such'portions of the chute as may extend55 beyond the frontend of the trough proper, means for supporting andangularly adjusting the supporting structure and means supporting theupper end of the chute supported by and angularly adjustable with thetrough supporting |30 structure.

' NORMAN F. S. RUSSELL.

t FREDERICK C. LANGENBERG.

